This invention, which resulted from a contract with the United States Department of Energy, relates to a means for shifting the wavelength of light and, more particularly, to a means for changing the wavelength of a laser beam so that the beam can be effectively used in a process for separating uranium isotopes.
As disclosed in U.S. Pat. No. 3,940,615, U.sup.235 can be separated from U.sup.238 by selectively ionizing the U.sup.235 isotope in a vapor containing both U.sup.235 and U.sup.238, this ionization being effected by passing a laser beam having a proper frequency (or wavelength) through the vapor. Doppler shifting of the wavelength of a laser beam to obtain an optimal light wavelength for ionizing U.sup.235 in such a separation process has been proposed heretofore. However, the applicant's are aware of no apparatus for Doppler shifting of the wavelength of light that has the features or advantages of apparatus constructed in accordance with the principles of their invention disclosed herein.